The invention relates to a knee protector for vehicle passengers comprising an air bag arranged in the foot area, respectively, in the lower region of the dashboard of a vehicle behind a cover plate, wherein the air bag, upon deployment and inflation, will act on the cover plate so that it becomes detached from the securing means and is moved as a load distribution plate in the direction toward the knees of the passenger.
A knee protector with the aforementioned features is known from European Patent Document 0 684 164 A1. This knee protector device a the cover plate which is integrated in the foot area of the vehicle at the dashboard, and behind the cover plate the air bag is arranged which is deployed in the case of an accident. When deployed, the air bag will inflate and will cause the cover plate to become separated because of the inflation pressure so that the cover plate is moved in the direction toward the knee of the passenger. This cover plate upon contact at the knees will act as a load distribution plate. The subsequent energy absorption of the knee protector is achieved, similar to the action of air bag devices acting on the torso of a passenger, in that the pressure acting on the load distribution plate and thus on the air bag will cause gas to be released from the air bag via openings provided in the device or because of the permeability of the fabric of the air bag. For limiting the displacement movement of the load distribution plate in the direction toward the knee of the passenger, the load distribution plate of the known knee protector device is connected by a cable portion to the securing device.
The known knee protector has the disadvantage that the movement of the load distribution plate depends on the inflation behavior of the air bag loading it, so that a non-directed (random) displacement of the load distribution plate cannot be prevented. There is, for example, the risk that the load distribution plate will impact the knee of the passenger with an edge instead of the plate surface. Moreover, movement of the passenger and the resulting pressure during the energy absorption phase of the air bag supporting the load distribution plate can result in lateral displacement causing non-uniform energy absorption.
Another knee protector device is known from Patent Document WO 97/09207 in which the load distribution plate is fixedly connected to the air bag or is a component of the air bag fabric. This also has the aforementioned disadvantage with respect to the inflation behavior or the behavior during energy absorption.
In European Patent Document 0 820 905 A1 a knee protector is disclosed in which the inflating air bag will cause a deformable portion of the dashboard to bulge outwardly in the direction toward the knees of the passenger whereby the air bag will not penetrate the respective portion in the dashboard. With such a device it is possible to realize only limited deformation strokes.